There is a free download file that will eliminate trees on final approach for FSX called Lumberjack. It would remove trees on your approach that would make landings difficult and clear the trees for either a 3 or 5 mile radius around the runway. Is this still necessary with P3DV4.2? Or has is been fixed with this version. If it has not been fixed, since we don't have and Addon/Scenery files that I can find, where would one install this great freeware addon?

Why would one want to remove autogen trees for 3 miles (!) around an airfield?
If you are in tree height above ground 3 miles ahead of the runway, you're definitely approaching too low.
Otherwise...
As for finding airports more easily by looking for punch-out holes in the autogen... there's the possibility to display the airspaces around airports in P3D and you'll see them from v-e-r-y far away - no need to remove ('precious'!) autogen.
Michael.

Hi Mike. FSX had trees that were not realistic as to their actual location of trees at the end of the runways. So.....to fix the problem someone created a small fix that would remove the trees where landing was impossible because of the close proximity of the trees to the end of the runways?

Regarding the fact that P3D contains nearly 25.000 airports, it's next to impossible to answer your question with 100% certainty.
As far as I have tried maybe between 100 and 200 airfields yet, there is indeed one or the other with trees in the approach. But I always considered them a challenge to get over or past them and land on the runway nevertheless.
No really requirement of Lumberjack (or similar) yet.
Michael.